Is intelligence correlated with voting for Kerry?
(Answer: Yes)

This thesis topic has been discussed as a "hoax" in the Economist, a leading British newsmagazine.
So I decided to run the statistics myself. It is not a hoax, and you can verify my results in a couple of minutes, or do it yourself in a couple of hours.

The graphs below correlate educational attainment versus voting behavior. "Educational attainment" means the percentage of people who graduated high school or college in a state. "Voting behavior" in this context means the percentage of people in a state who voted for Kerry.

The theory is that educational attainment is a proxy for intelligence (or perhaps more accurately, for wisdom), and that therefore, if the thesis is true, then higher educational attainment will correlate with higher voting rates for Kerry.

On a state-by-state basis, this is unambiguously true. The higher the education level in a state, the more likely that state was to vote for Kerry in 2004. Specifically:

-0.01 High School correlation: There is no correlation between getting a high-school degree and voting behavior. This is the reason people have called the Economist article a hoax. It just means the Economist did not look at enough data -- probably because almost everyone gets a high school degree these days. I consider the hoax outline and hoax analysis to be flawed because IQ measured in grade school is irrelevant to adult voting behavior -- the measurement is made too early and should not be done on IQ per se. Intelligence measured later in life, by academic accompishment, is a better measurement and DOES correlate with voting behavior.

0.12 college correlation: There is only a minimal correlation between some college attendance and voting behavior. This would not of itself be sufficient to draw any conclusions.

0.64 B.A. degree correlation: There is a good correlation between getting a Bachelor's degree and voting for Kerry. The more people in your state who got college degrees, the more likely that your state voted for Kerry.

0.77 Advanced Degree correlation: There is a strong correlation between receiving an advanced degree and voting for Kerry. The trend of increasing correlation in the three results indicates to me that there is a strong correlation between more education and voting for Kerry.

How to read the charts:
- Each spot represents one state.
- The Y axis (vertical) is one measure of educational attainment.
- The X axis (horizontal) is the percentage of people voting for Kerry.
- A high correlation coefficient means more educational attainment correlates with more Kerry votes.
- The blue line is the "best fit" line. It shows the trend of the points in a mathemaically verifiable way. The slope indicates the correlation.
- The pink lines are one standard deviation from the blue lines. They show how tight the data points are, which is a way of showing how much margin of error there is.
- Correlation is not causation, of course, but the bottom line is, the more people your state has with higher education, the more your state voted for Kerry.
- The outlier on the far right of each chart is D.C., which voted 86% for Kerry.
- The raw data and source citations are at the bottom.

Kerry vote vs. H.S. degrees

Each state's voting percentage for Kerry (Y) versus percentage of population in that state who have obtained a High School degree or more (X).

Conclusion: There is no correlation between the number of high school grads in a state and the Kerry vote. The percentage of high school grads in a state has no influence on the percentage who voted for Kerry.

The blue line is the least squares best fit to the data (points).

The pink lines have slopes 1 sigma away from the best fit. They intersect at the mean of x and y for the data.

number of events entered: 51

slope: -0.00 +/- 0.05

y intercept: 86.24 +/- 0.09

dispersion: 2.44

correlation coefficient: -0.01

chi ^ 2 (degrees of freedom): 694.0 ( 49)

Kerry vote vs. some college

Each state's voting percentage for Kerry (Y) versus percentage of population in that state who have attended some college(X).

Conclusion: There is a minimal correlation between the number of people in a state and the Kerry vote. The percentage of people attending college in a state has hardly any influence on the percentage who voted for Kerry.

The blue line is the least squares best fit to the data (points).

The pink lines have slopes 1 sigma away from the best fit. They intersect at the mean of x and y for the data.

number of events entered: 51

slope: 0.07 +/- 0.08

y intercept: 48.86 +/- 0.09

dispersion: 3.96

correlation coefficient: 0.12

chi ^ 2 (degrees of freedom): 1822.7 ( 49)

Kerry vote vs. B.A. degrees

Each state's voting percentage for Kerry (Y) versus percentage of population in that state who have obtained a Bachelor's degree or more (X).

Conclusion: There is a good correlation between the number of college grads in a state and the Kerry vote. The more college grads, the more likely that state was to vote for Kerry.

The blue line is the least squares best fit to the data (points).

The pink lines have slopes 1 sigma away from the best fit. They intersect at the mean of x and y for the data.

number of events entered: 51

slope: 0.34 +/- 0.06

y intercept: 10.76 +/- 0.09

dispersion: 2.83

correlation coefficient: 0.64

chi ^ 2 (degrees of freedom): 936.1 ( 49)

Kerry vote vs. advanced degrees

Each state's voting percentage for Kerry (Y) versus percentage of population in that state who have obtained an advanced degree or more (X).

Conclusion: There is a high correlation between the number of people with advanced degrees in a state and the Kerry vote.

The blue line is the least squares best fit to the data (points).

The pink lines have slopes 1 sigma away from the best fit. They intersect at the mean of x and y for the data.

number of events entered: 51

slope: 0.20 +/- 0.02

y intercept: -0.61 +/- 0.09

dispersion: 1.12

correlation coefficient: 0.77

chi ^ 2 (degrees of freedom): 147.1 ( 49)

Source Citations

This analysis was very obvious to me because I did the same analysis in 2000 for the Gore vote, with much the same results, on the wonderful but now-defunct website www.AskMe.com.
- Please do not write me saying this is a hoax unless you go to the original source materials cited below and do your own analysis and come up with different results (which you won't).
- Please do not write me explaining that correlation is not causation. I'm well aware that these results do not mean that getting a degree makes one vote Democratic. It is more likely that getting a degree makes one reject simplistic populism in favor of issue-based analysis, makes one more likely to live in cities, and makes one gravitate to the more college-dense and simultaneously more Democratic states on the coasts and Great Lakes -- and that those things are much more causative than the degree itself. I know all that so please don't tell me it again.
- If you would like to write a thoughtful rebuttal, please do so and I'll post it here.

All statistical analysis uses the correlation tool at http://guernsey.uoregon.edu/~dmason/stat/correl.html

Voting results from David Leip, http://www.uselectionatlas.org/USPRESIDENT/data.php?&year=2004&datatype=national&def=1&f=0

2003 Educational Attainment levels (High School and BA tables) from Table 13 of the U.S. Census Bureau Internet Release date: June 29, 2004 at http://www.census.gov/population/www/socdemo/educ-attn.html

2000 data (Advanced degrees and some-college tables) from www.census.gov/prod/cen2000/doc/sf3.pdf - Educational Attainment of the Population 25 Years and Over for the United States, Regions, and States, and for Puerto Rico: 1990 and 2000

Math workup is in the spreadsheet www.OnTheIssues.org/AskMe/Education_vs_Party.xls -- all workup done by the author.